/* Copyright (C) 2009 Red Hat, Inc.
 * Author: Michael S. Tsirkin <mst@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 *
 * virtio-net server in host kernel.
 */

#include <linux/compat.h>
#include <linux/eventfd.h>
#include <linux/vhost.h>
#include <linux/virtio_net.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/rcupdate.h>
#include <linux/file.h>
#include <linux/slab.h>

#include <linux/net.h>
#include <linux/if_packet.h>
#include <linux/if_arp.h>
#include <linux/if_tun.h>
#include <linux/if_macvlan.h>

#include <net/sock.h>
#include <linux/tcp.h>
#include <linux/ip.h>
//#include <linux/socket.h>
//#include <linux/syscalls.h>
#include "vhost.h"
//extern long sys_socket(int,int,int)
#include <linux/proc_fs.h>	/* Necessary because we use the proc fs */
#include <linux/seq_file.h>	/* for seq_file */
#include <linux/utsname.h>
#include <linux/spinlock.h>
#include <linux/list.h>

#define system_utsname init_uts_ns.name

char *recordlist=NULL;
int proc_read_status = 0;
int proc_write_status = 0;
long recordlist_offset = 0;
long previous_recordlist_offset = 0;
long proc_offset = 0;
spinlock_t proc_lock;
//static char my_buffer[1024*1024];
#define PROCFS_MAX_SIZE	 PAGE_SIZE
static char vhost_ctl_buf[PROCFS_MAX_SIZE];
static unsigned long procfs_buffer_size = 0;
int vhost_trace_enable = 0;
int num_active_traces = 0;

/* Private Data structure */
struct _mydrv_struct {
/* … */
struct list_head list; /* Link */
char info [256]; /* Info to pass via procfs/seq files */
/* … */
} mydrv_struct;
struct _mydrv_struct *mydrv_new;

static LIST_HEAD (mydrv_list); /* List Head */

#define NIPQUAD(addr) \
    ((unsigned char *)&addr)[0], \
    ((unsigned char *)&addr)[1], \
    ((unsigned char *)&addr)[2], \
    ((unsigned char *)&addr)[3]

#define NIP6(addr) \
    ntohs((addr).s6_addr16[0]), \
    ntohs((addr).s6_addr16[1]), \
    ntohs((addr).s6_addr16[2]), \
    ntohs((addr).s6_addr16[3]), \
    ntohs((addr).s6_addr16[4]), \
    ntohs((addr).s6_addr16[5]), \
    ntohs((addr).s6_addr16[6]), \
    ntohs((addr).s6_addr16[7])

static int experimental_zcopytx;
module_param(experimental_zcopytx, int, 0444);
MODULE_PARM_DESC(experimental_zcopytx, "Enable Experimental Zero Copy TX");

/* Max number of bytes transferred before requeueing the job.
 * Using this limit prevents one virtqueue from starving others. */
#define VHOST_NET_WEIGHT 0x80000

/* MAX number of TX used buffers for outstanding zerocopy */
#define VHOST_MAX_PEND 128
#define VHOST_GOODCOPY_LEN 256

enum {
	VHOST_NET_VQ_RX = 0,
	VHOST_NET_VQ_TX = 1,
	VHOST_NET_VQ_MAX = 2,
};

enum vhost_net_poll_state {
	VHOST_NET_POLL_DISABLED = 0,
	VHOST_NET_POLL_STARTED = 1,
	VHOST_NET_POLL_STOPPED = 2,
};

struct vhost_net {
	struct vhost_dev dev;
	struct vhost_virtqueue vqs[VHOST_NET_VQ_MAX];
	struct vhost_poll poll[VHOST_NET_VQ_MAX];
	/* Tells us whether we are polling a socket for TX.
	 * We only do this when socket buffer fills up.
	 * Protected by tx vq lock. */
	enum vhost_net_poll_state tx_poll_state;
};

static bool vhost_sock_zcopy(struct socket *sock)
{
	return unlikely(experimental_zcopytx) &&
		sock_flag(sock->sk, SOCK_ZEROCOPY);
}

/* Pop first len bytes from iovec. Return number of segments used. */
static int move_iovec_hdr(struct iovec *from, struct iovec *to,
			  size_t len, int iov_count)
{
	int seg = 0;
	size_t size;

	while (len && seg < iov_count) {
		size = min(from->iov_len, len);
		to->iov_base = from->iov_base;
		to->iov_len = size;
		from->iov_len -= size;
		from->iov_base += size;
		len -= size;
		++from;
		++to;
		++seg;
	}
	return seg;
}
/* Copy iovec entries for len bytes from iovec. */
static void copy_iovec_hdr(const struct iovec *from, struct iovec *to,
			   size_t len, int iovcount)
{
	int seg = 0;
	size_t size;

	while (len && seg < iovcount) {
		size = min(from->iov_len, len);
		to->iov_base = from->iov_base;
		to->iov_len = size;
		len -= size;
		++from;
		++to;
		++seg;
	}
}

/* Caller must have TX VQ lock */
static void tx_poll_stop(struct vhost_net *net)
{
	if (likely(net->tx_poll_state != VHOST_NET_POLL_STARTED))
		return;
	vhost_poll_stop(net->poll + VHOST_NET_VQ_TX);
	net->tx_poll_state = VHOST_NET_POLL_STOPPED;
}

/* Caller must have TX VQ lock */
static void tx_poll_start(struct vhost_net *net, struct socket *sock)
{
	if (unlikely(net->tx_poll_state != VHOST_NET_POLL_STOPPED))
		return;
	vhost_poll_start(net->poll + VHOST_NET_VQ_TX, sock->file);
	net->tx_poll_state = VHOST_NET_POLL_STARTED;
}

/*static void peek_txhead_len(struct sock *sk)
{
        struct sk_buff *head;
        int len = 0;
        unsigned long flags;

        int sport, dport; // source & dest port
        struct tcphdr *tcp_header;     // tcp header struct
        struct iphdr *network_header;

        //spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
        //head = skb_peek(&sk->sk_receive_queue);
				spin_lock_irqsave(&sk->sk_write_queue.lock, flags);
				head = skb_peek(&sk->sk_write_queue);
				head = sk->sk_send_head;
				//spin_lock_irqsave(&sk->sk_async_wait_queue.lock, flags);
				//head = skb_peek(&sk->sk_async_wait_queue);
        //if (likely(head)) {
        //        len = head->len;
        //        if (vlan_tx_tag_present(head))
        //                len += VLAN_HLEN;
        //}

        if(head==NULL)
                printk("tx:null head\n");
        else {
                network_header = (struct iphdr *)skb_network_header(head);
                if (network_header && network_header->protocol && (network_header->protocol == IPPROTO_TCP)) {
                        if (network_header->protocol==IPPROTO_TCP) {
                                tcp_header = (struct tcphdr *)skb_transport_header(head);
                                sport = ntohs((unsigned short int) tcp_header->source);
                                dport = ntohs((unsigned short int) tcp_header->dest);
                        }
                        printk("tx:source:%d.%d.%d.%d:,dest:%d.%d.%d.%d\n", NIPQUAD(network_header->saddr), NIPQUAD(network_header->daddr));
                        printk("sport:%d,dport:%d\n",sport,dport);
                }
        }

        //spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
				spin_unlock_irqrestore(&sk->sk_write_queue.lock, flags);
				//spin_unlock_irqrestore(&sk->sk_async_wait_queue.lock, flags);
        //return len;
}*/

void Disconnect_from_Server(struct socket * sock, int result)
{
	//struct socket *
	if(sock==NULL)
		return;
	sock_release(sock);
}

int procfile_read(char *page, char **start, off_t offset, int count, int *eof, void *data) {
	//unsigned long flags;
	off_t thischunk_start = 0;
	off_t thischunk_len = 0;
	struct _mydrv_struct *p;

	/* Loop thru the list grabbing device info */
	list_for_each_entry (p, &mydrv_list, list) {
	thischunk_len += sprintf (page+thischunk_len, p->info);

	/* Advance thischunk_start only to the extent that the next
	* read will not result in total bytes more than (offset+count)
	*/
	if (thischunk_start + thischunk_len < offset) {
		thischunk_start += thischunk_len;
		thischunk_len = 0;
	} else if (thischunk_start + thischunk_len > offset+count) {
		break;
	} else {
		continue;
		}
	}

	/* Actual start */
	*start = page + (offset - thischunk_start);
	/* Calculate number of written bytes */
	thischunk_len -= (offset-thischunk_start);
	if (thischunk_len > count) {
		thischunk_len = count;
	} else {
		*eof = 1;
		list_del_init(&mydrv_list);
	}

	return thischunk_len;
	/*if(counter == 0) {
		if(recordlist_offset != 0) {
		spin_lock_irqsave(&proc_lock, flags);
		len = sprintf(my_buffer,"%s", recordlist);

		previous_recordlist_offset = recordlist_offset;
		printk("thischunk_len=%d, recordlist_offset=%d, counter=%d\n", thischunk_len, recordlist_offset, counter);

		kfree(recordlist);
		recordlist = (char *)kmalloc(1024*1024, GFP_KERNEL);
		recordlist_offset = 0;
		counter = 1;
		spin_unlock_irqrestore(&proc_lock, flags);
		}
		else {
			counter = 0;
			*eof = 1;
			return 0;
		}
	}
	if(counter == 1) {
	}*/

	/*int len = 0;
	int buffer_length = 3000; //must be smaller than 3072
	unsigned long flags;
	proc_read_status = 1;
	static char unit_buffer[3000];
	static char my_buffer[1024*1024];

	if(counter == 0) {
		if(recordlist_offset != 0) {
		spin_lock_irqsave(&proc_lock, flags);
		len = sprintf(my_buffer,"%s", recordlist);
		// *start = my_buffer;
		previous_recordlist_offset = recordlist_offset;
		printk("len=%d, recordlist_offset=%d, counter=%d\n", len, recordlist_offset, counter);
		//printk("len=%d, counter = %d\n%s", len, counter, my_buffer);
		kfree(recordlist);
		recordlist = (char *)kmalloc(1024*1024, GFP_KERNEL);
		recordlist_offset = 0;
		counter = 1;
		spin_unlock_irqrestore(&proc_lock, flags);
		}
		else {
			counter = 0;
			*eof = 1;
			return 0;
		}
	}
	if(counter == 1) {
			if(proc_offset>=strlen(my_buffer)) {
				proc_offset = 0;
				counter == 0;
				*eof = 1;
				return 0;
			}
			len = snprintf(page,buffer_length,"%s", my_buffer+proc_offset);
			printk("len=%d, proc_offset=%d, counter=%d\n", len, proc_offset, counter);
			proc_offset = proc_offset + len;
			if(len<buffer_length)
				*eof = 1;
			//page=unit_buffer;
			return len;
	}*/
	
	/*counter++;
	if (off > 0)
	{
		printk("offset=%d\n", off);
		*start = page;
		previous_recordlist_offset = previous_recordlist_offset-off;
		return previous_recordlist_offset;
	}
	else {
		spin_lock_irqsave(&proc_lock, flags);
		if(recordlist_offset != 0) {
		len = sprintf(my_buffer,"%s", recordlist);
		*start = my_buffer;
		previous_recordlist_offset = recordlist_offset;
		printk("len=%d, recordlist_offset=%d\n", len, recordlist_offset);
		//printk("len=%d, counter = %d\n%s", len, counter, my_buffer);
		kfree(recordlist);
		recordlist = (char *)kmalloc(1024*1024, GFP_KERNEL);
		recordlist_offset = 0;
		}
		spin_unlock_irqrestore(&proc_lock, flags);
	
	proc_read_status = 0;
	*eof = 1;
	}
	return len;*/
}

int truncate_list()
{
	struct list_head *pos,*n;
	struct _mydrv_struct *p;
	list_for_each_safe(pos, n, &(mydrv_list))
	{
		p = list_entry(pos, struct _mydrv_struct, list);
		list_del(pos);
		kfree(p);
	}
	if(list_empty(&(mydrv_list))) {
		printk("mydrv_list for vhost is empty\n");
	}
	return 0;
}

ssize_t
ctl_procfile_read(char *buffer,
	      char **buffer_location,
	      off_t offset, int buffer_length, int *eof, void *data)
{
	int len;		/* The number of bytes actually used */

	/*
	 * It's static so it will still be in memory
	 * when we leave this function
	 */
	static char my_buffer[80];

	static int count = 1;

	/*
	 * We give all of our information in one go, so if the anybody asks us
	 * if we have more information the answer should always be no.
	 */
	if (offset > 0)
		return 0;

	/*
	 * Fill the buffer and get its length
	 */
	len = sprintf(my_buffer, "%d", num_active_traces);
	count++;

	/*
	 * Tell the function which called us where the buffer is
	 */
	*buffer_location = my_buffer;

	/*
	 * Return the length
	 */
	return len;
}

int ctl_procfile_write(struct file *file, const char *buffer, unsigned long count, void *data)
{
	//memset(vhost_ctl_buf, 0, PAGE_SIZE);
	//if(copy_from_user(vhost_ctl_buf, buf, len))
	/* get buffer size */
	procfs_buffer_size = count;
	if (procfs_buffer_size > PROCFS_MAX_SIZE ) {
		procfs_buffer_size = PROCFS_MAX_SIZE;
	}
	/* write data to the buffer */
	if ( copy_from_user(vhost_ctl_buf, buffer, procfs_buffer_size) ) {
		return -EFAULT;
	}
	printk("ctl:%s\n", vhost_ctl_buf);
	if(strncmp(vhost_ctl_buf, "1", 1) == 0) {
		if(vhost_trace_enable == 0) {
			printk("vhost tracing started\n");
		}
		else {
			printk("vhost tracing already running\n");
		}
		vhost_trace_enable = 1;
		num_active_traces ++;
		printk("number of active tracing after enable:%d\n", num_active_traces);
	}
	else {
		num_active_traces --;
		printk("number of active tracing after disable:%d\n", num_active_traces);
		if(num_active_traces <= 0) {
			printk("vhost tracing stopped\n");
			vhost_trace_enable = 0;
			num_active_traces = 0;
			truncate_list();
		}
	}
	return procfs_buffer_size;
}

static int print_packet_header(struct iovec *sg)
{
	unsigned int highbyte, lowbyte;
	unsigned int highbyte1, lowbyte1;
	//unsigned int highbyte2, lowbyte2;
	unsigned int high4bite, low4bite;
	//unsigned int high4bite1, low4bite1;
	//unsigned int high4bite2, low4bite2;
	unsigned int firstbyte, secondbyte, thirdbyte, fouthbyte;
	unsigned int firstbyte1, secondbyte1, thirdbyte1, fouthbyte1;
	//unsigned int firstbyte2, secondbyte2, thirdbyte2, fouthbyte2;
	//long int sourceport;
	//long int destport;

	struct timeval tv;
	unsigned long flags;

	highbyte = ((unsigned char*)(sg)->iov_base)[12];
	lowbyte = ((unsigned char*)(sg)->iov_base)[13];
	if(highbyte == 0x08 && lowbyte == 0x06)
	{
		//printk("SKIP ARP\n");
		return 0;
	}

	high4bite = (((unsigned char*)(sg)->iov_base)[14])>>4;
	low4bite = (((unsigned char*)(sg)->iov_base)[14]) & 0x0f;
	//printf("version:%02x,length:%d\n", high4bite, low4bite*4);//RFC 894

	firstbyte = ((unsigned char*)(sg)->iov_base)[26];
	secondbyte = ((unsigned char*)(sg)->iov_base)[27];
	thirdbyte = ((unsigned char*)(sg)->iov_base)[28];
	fouthbyte = ((unsigned char*)(sg)->iov_base)[29];
	/////printk("txsource ip:%d.%d.%d.%d\n", firstbyte, secondbyte, thirdbyte, fouthbyte);

	/*highbyte1 = ((unsigned char*)(sg)->iov_base)[low4bite*4+14];
	lowbyte1 = ((unsigned char*)(sg)->iov_base)[low4bite*4+15];
	//sourceport = highbyte1*256+lowbyte1;
	printf("source port:%d\n", highbyte1*256+lowbyte1);*/

	firstbyte1 = ((unsigned char*)(sg)->iov_base)[30];
	secondbyte1 = ((unsigned char*)(sg)->iov_base)[31];
	thirdbyte1 = ((unsigned char*)(sg)->iov_base)[32];
	fouthbyte1 = ((unsigned char*)(sg)->iov_base)[33];
	/////printk("txdest ip:%d.%d.%d.%d\n", firstbyte1, secondbyte1, thirdbyte1, fouthbyte1);

	highbyte = ((unsigned char*)(sg)->iov_base)[low4bite*4+14];
	lowbyte = ((unsigned char*)(sg)->iov_base)[low4bite*4+15];
	//sourceport = highbyte1*256+lowbyte1;
	/////printk("txsource port:%d\n", highbyte*256+lowbyte);
	highbyte1 = ((unsigned char*)(sg)->iov_base)[low4bite*4+16];
	lowbyte1 = ((unsigned char*)(sg)->iov_base)[low4bite*4+17];
	//destport = highbyte2*256+lowbyte2;
	/////printk("txdest port:%d\n", highbyte1*256+lowbyte1);

	do_gettimeofday(&tv);
	spin_lock_irqsave(&proc_lock, flags);
	if((highbyte*256+lowbyte)!=0&&(highbyte1*256+lowbyte1)!=0) {
		mydrv_new = kmalloc (sizeof (mydrv_struct), GFP_ATOMIC);
		if(mydrv_new!=NULL) {
		//sprintf (mydrv_new->info, "(%s)(TX)(%d.%d.%d.%d)(%d)(%d.%d.%d.%d)(%d)(%ld.%ld)\n",system_utsname.nodename, firstbyte, secondbyte, thirdbyte, fouthbyte, highbyte*256+lowbyte, firstbyte1, secondbyte1, thirdbyte1, fouthbyte1, highbyte1*256+lowbyte1, tv.tv_sec, tv.tv_usec);
		sprintf (mydrv_new->info, "%s:TX:%d.%d.%d.%d:%d:%d.%d.%d.%d:%d:%ld:%ld\n",system_utsname.nodename, firstbyte, secondbyte, thirdbyte, fouthbyte, highbyte*256+lowbyte, firstbyte1, secondbyte1, thirdbyte1, fouthbyte1, highbyte1*256+lowbyte1, tv.tv_sec, tv.tv_usec);
		list_add_tail (&mydrv_new->list, &mydrv_list);
		}
	//recordlist_offset += sprintf(recordlist+recordlist_offset, "(%s)TX:(%d.%d.%d.%d)(%d)(%d.%d.%d.%d)(%d)(%ld.%ld)\n",system_utsname.nodename, firstbyte, secondbyte, thirdbyte, fouthbyte, highbyte*256+lowbyte, firstbyte1, secondbyte1, thirdbyte1, fouthbyte1, highbyte1*256+lowbyte1, tv.tv_sec, tv.tv_usec);
	}
	spin_unlock_irqrestore(&proc_lock, flags);

	return 0;
}

/* Expects to be always run from workqueue - which acts as
 * read-size critical section for our kind of RCU. */
static void handle_tx(struct vhost_net *net)
{
	struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
	unsigned out, in, s;
	int head;
	struct msghdr msg = {
		.msg_name = NULL,
		.msg_namelen = 0,
		.msg_control = NULL,
		.msg_controllen = 0,
		.msg_iov = vq->iov,
		.msg_flags = MSG_DONTWAIT,
	};
	size_t len, total_len = 0;
	int err, wmem;
	size_t hdr_size;
	struct socket *sock;
	struct vhost_ubuf_ref *uninitialized_var(ubufs);
	bool zcopy;

	/* TODO: check that we are running from vhost_worker? */
	sock = rcu_dereference_check(vq->private_data, 1);
	if (!sock)
		return;

	wmem = atomic_read(&sock->sk->sk_wmem_alloc);
	if (wmem >= sock->sk->sk_sndbuf) {
		mutex_lock(&vq->mutex);
		tx_poll_start(net, sock);
		mutex_unlock(&vq->mutex);
		return;
	}

	mutex_lock(&vq->mutex);
	vhost_disable_notify(&net->dev, vq);

	if (wmem < sock->sk->sk_sndbuf / 2)
		tx_poll_stop(net);
	hdr_size = vq->vhost_hlen;
	zcopy = vhost_sock_zcopy(sock);

	for (;;) {
		/* Release DMAs done buffers first */
		if (zcopy)
			vhost_zerocopy_signal_used(vq);

		head = vhost_get_vq_desc(&net->dev, vq, vq->iov,
					 ARRAY_SIZE(vq->iov),
					 &out, &in,
					 NULL, NULL);
		/* On error, stop handling until the next kick. */
		if (unlikely(head < 0))
			break;
		/* Nothing new?  Wait for eventfd to tell us they refilled. */
		if (head == vq->num) {
			int num_pends;

			wmem = atomic_read(&sock->sk->sk_wmem_alloc);
			if (wmem >= sock->sk->sk_sndbuf * 3 / 4) {
				tx_poll_start(net, sock);
				set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
				break;
			}
			/* If more outstanding DMAs, queue the work.
			 * Handle upend_idx wrap around
			 */
			num_pends = likely(vq->upend_idx >= vq->done_idx) ?
				    (vq->upend_idx - vq->done_idx) :
				    (vq->upend_idx + UIO_MAXIOV - vq->done_idx);
			if (unlikely(num_pends > VHOST_MAX_PEND)) {
				tx_poll_start(net, sock);
				set_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
				break;
			}
			if (unlikely(vhost_enable_notify(&net->dev, vq))) {
				vhost_disable_notify(&net->dev, vq);
				continue;
			}
			break;
		}
		if (in) {
			vq_err(vq, "Unexpected descriptor format for TX: "
			       "out %d, int %d\n", out, in);
			break;
		}
		/* Skip header. TODO: support TSO. */
		s = move_iovec_hdr(vq->iov, vq->hdr, hdr_size, out);
		msg.msg_iovlen = out;
		len = iov_length(vq->iov, out);
		/* Sanity check */
		if (!len) {
			vq_err(vq, "Unexpected header len for TX: "
			       "%zd expected %zd\n",
			       iov_length(vq->hdr, s), hdr_size);
			break;
		}
		/* use msg_control to pass vhost zerocopy ubuf info to skb */
		if (zcopy) {
			vq->heads[vq->upend_idx].id = head;
			if (len < VHOST_GOODCOPY_LEN) {
				/* copy don't need to wait for DMA done */
				vq->heads[vq->upend_idx].len =
							VHOST_DMA_DONE_LEN;
				msg.msg_control = NULL;
				msg.msg_controllen = 0;
				ubufs = NULL;
			} else {
				struct ubuf_info *ubuf;
				ubuf = vq->ubuf_info + vq->upend_idx;

				vq->heads[vq->upend_idx].len = len;
				ubuf->callback = vhost_zerocopy_callback;
				ubuf->arg = vq->ubufs;
				ubuf->desc = vq->upend_idx;
				msg.msg_control = ubuf;
				msg.msg_controllen = sizeof(ubuf);
				ubufs = vq->ubufs;
				kref_get(&ubufs->kref);
			}
			vq->upend_idx = (vq->upend_idx + 1) % UIO_MAXIOV;
		}
		//printk("msg.msg_iovlen:%d\n", msg.msg_iovlen);
		if(vhost_trace_enable == 1) {
			if(msg.msg_iovlen==2)
				print_packet_header(&(msg.msg_iov[1]));
		}
		/* TODO: Check specific error and bomb out unless ENOBUFS? */
		err = sock->ops->sendmsg(NULL, sock, &msg, len);
		if (unlikely(err < 0)) {
			if (zcopy) {
				if (ubufs)
					vhost_ubuf_put(ubufs);
				vq->upend_idx = ((unsigned)vq->upend_idx - 1) %
					UIO_MAXIOV;
			}
			vhost_discard_vq_desc(vq, 1);
			tx_poll_start(net, sock);
			break;
		}
		if (err != len)
			pr_debug("Truncated TX packet: "
				 " len %d != %zd\n", err, len);
		if (!zcopy)
			vhost_add_used_and_signal(&net->dev, vq, head, 0);
		total_len += len;
		if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
			vhost_poll_queue(&vq->poll);
			break;
		}
	}

	mutex_unlock(&vq->mutex);
}

static int peek_head_len(struct sock *sk)
{
	struct sk_buff *head;
	int len = 0;
	unsigned long flags;
	unsigned long proc_flags;

	int sport, dport; // source & dest port
	struct tcphdr *tcp_header;     // tcp header struct
	struct iphdr *network_header;

	struct timeval tv;

	spin_lock_irqsave(&sk->sk_receive_queue.lock, flags);
	head = skb_peek(&sk->sk_receive_queue);
	if (likely(head))
		len = head->len;

	if(vhost_trace_enable == 1) {
	if(head==NULL) {
		/////printk("null head\n");
	}
	else {
		network_header = (struct iphdr *)skb_network_header(head);
		if (network_header && network_header->protocol && (network_header->protocol == IPPROTO_TCP)) {
			if (network_header->protocol==IPPROTO_TCP) {
				tcp_header = (struct tcphdr *)skb_transport_header(head);
				sport = ntohs((unsigned short int) tcp_header->source);
				dport = ntohs((unsigned short int) tcp_header->dest);
			}
			/////printk("rx:source:%d.%d.%d.%d:,dest:%d.%d.%d.%d\n", NIPQUAD(network_header->saddr), NIPQUAD(network_header->daddr));
			/////printk("sport:%d,dport:%d\n",sport,dport);

				do_gettimeofday(&tv);
				spin_lock_irqsave(&proc_lock, proc_flags);
				if(sport!=0&&dport!=0) {
				mydrv_new = kmalloc (sizeof (mydrv_struct), GFP_ATOMIC);
				//sprintf (mydrv_new->info, "(%s)(RX)(%d.%d.%d.%d)(%d)(%d.%d.%d.%d)(%d)(%ld.%ld)\n", system_utsname.nodename, NIPQUAD(network_header->saddr), sport, NIPQUAD(network_header->daddr), dport, tv.tv_sec, tv.tv_usec);
				sprintf (mydrv_new->info, "%s:RX:%d.%d.%d.%d:%d:%d.%d.%d.%d:%d:%ld:%ld\n", system_utsname.nodename, NIPQUAD(network_header->saddr), sport, NIPQUAD(network_header->daddr), dport, tv.tv_sec, tv.tv_usec);
				list_add_tail (&mydrv_new->list, &mydrv_list);
				//recordlist_offset += sprintf(recordlist+recordlist_offset, "(%s)RX:(%d.%d.%d.%d)(%d)(%d.%d.%d.%d)(%d)(%ld.%ld)\n", system_utsname.nodename, NIPQUAD(network_header->saddr), sport, NIPQUAD(network_header->daddr), dport, tv.tv_sec, tv.tv_usec);
				}
				spin_unlock_irqrestore(&proc_lock, proc_flags);
		}
	}
	}

	spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags);
	return len;
}

/* This is a multi-buffer version of vhost_get_desc, that works if
 *	vq has read descriptors only.
 * @vq		- the relevant virtqueue
 * @datalen	- data length we'll be reading
 * @iovcount	- returned count of io vectors we fill
 * @log		- vhost log
 * @log_num	- log offset
 * @quota       - headcount quota, 1 for big buffer
 *	returns number of buffer heads allocated, negative on error
 */
static int get_rx_bufs(struct vhost_virtqueue *vq,
		       struct vring_used_elem *heads,
		       int datalen,
		       unsigned *iovcount,
		       struct vhost_log *log,
		       unsigned *log_num,
		       unsigned int quota)
{
	unsigned int out, in;
	int seg = 0;
	int headcount = 0;
	unsigned d;
	int r, nlogs = 0;

	while (datalen > 0 && headcount < quota) {
		if (unlikely(seg >= UIO_MAXIOV)) {
			r = -ENOBUFS;
			goto err;
		}
		d = vhost_get_vq_desc(vq->dev, vq, vq->iov + seg,
				      ARRAY_SIZE(vq->iov) - seg, &out,
				      &in, log, log_num);
		if (d == vq->num) {
			r = 0;
			goto err;
		}
		if (unlikely(out || in <= 0)) {
			vq_err(vq, "unexpected descriptor format for RX: "
				"out %d, in %d\n", out, in);
			r = -EINVAL;
			goto err;
		}
		if (unlikely(log)) {
			nlogs += *log_num;
			log += *log_num;
		}
		heads[headcount].id = d;
		heads[headcount].len = iov_length(vq->iov + seg, in);
		datalen -= heads[headcount].len;
		++headcount;
		seg += in;
	}
	heads[headcount - 1].len += datalen;
	*iovcount = seg;
	if (unlikely(log))
		*log_num = nlogs;
	return headcount;
err:
	vhost_discard_vq_desc(vq, headcount);
	return r;
}

/* Expects to be always run from workqueue - which acts as
 * read-size critical section for our kind of RCU. */
static void handle_rx(struct vhost_net *net)
{
	struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
	unsigned uninitialized_var(in), log;
	struct vhost_log *vq_log;
	struct msghdr msg = {
		.msg_name = NULL,
		.msg_namelen = 0,
		.msg_control = NULL, /* FIXME: get and handle RX aux data. */
		.msg_controllen = 0,
		.msg_iov = vq->iov,
		.msg_flags = MSG_DONTWAIT,
	};
	struct virtio_net_hdr_mrg_rxbuf hdr = {
		.hdr.flags = 0,
		.hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE
	};
	size_t total_len = 0;
	int err, mergeable;
	s16 headcount;
	size_t vhost_hlen, sock_hlen;
	size_t vhost_len, sock_len;
	/* TODO: check that we are running from vhost_worker? */
	struct socket *sock = rcu_dereference_check(vq->private_data, 1);

	if (!sock)
		return;

	mutex_lock(&vq->mutex);
	vhost_disable_notify(&net->dev, vq);
	vhost_hlen = vq->vhost_hlen;
	sock_hlen = vq->sock_hlen;

	vq_log = unlikely(vhost_has_feature(&net->dev, VHOST_F_LOG_ALL)) ?
		vq->log : NULL;
	mergeable = vhost_has_feature(&net->dev, VIRTIO_NET_F_MRG_RXBUF);

	while ((sock_len = peek_head_len(sock->sk))) {
		sock_len += sock_hlen;
		vhost_len = sock_len + vhost_hlen;
		headcount = get_rx_bufs(vq, vq->heads, vhost_len,
					&in, vq_log, &log,
					likely(mergeable) ? UIO_MAXIOV : 1);
		/* On error, stop handling until the next kick. */
		if (unlikely(headcount < 0))
			break;
		/* OK, now we need to know about added descriptors. */
		if (!headcount) {
			if (unlikely(vhost_enable_notify(&net->dev, vq))) {
				/* They have slipped one in as we were
				 * doing that: check again. */
				vhost_disable_notify(&net->dev, vq);
				continue;
			}
			/* Nothing new?  Wait for eventfd to tell us
			 * they refilled. */
			break;
		}
		/* We don't need to be notified again. */
		if (unlikely((vhost_hlen)))
			/* Skip header. TODO: support TSO. */
			move_iovec_hdr(vq->iov, vq->hdr, vhost_hlen, in);
		else
			/* Copy the header for use in VIRTIO_NET_F_MRG_RXBUF:
			 * needed because recvmsg can modify msg_iov. */
			copy_iovec_hdr(vq->iov, vq->hdr, sock_hlen, in);
		msg.msg_iovlen = in;
		err = sock->ops->recvmsg(NULL, sock, &msg,
					 sock_len, MSG_DONTWAIT | MSG_TRUNC);
		/* Userspace might have consumed the packet meanwhile:
		 * it's not supposed to do this usually, but might be hard
		 * to prevent. Discard data we got (if any) and keep going. */
		if (unlikely(err != sock_len)) {
			pr_debug("Discarded rx packet: "
				 " len %d, expected %zd\n", err, sock_len);
			vhost_discard_vq_desc(vq, headcount);
			continue;
		}
		if (unlikely(vhost_hlen) &&
		    memcpy_toiovecend(vq->hdr, (unsigned char *)&hdr, 0,
				      vhost_hlen)) {
			vq_err(vq, "Unable to write vnet_hdr at addr %p\n",
			       vq->iov->iov_base);
			break;
		}
		/* TODO: Should check and handle checksum. */
		if (likely(mergeable) &&
		    memcpy_toiovecend(vq->hdr, (unsigned char *)&headcount,
				      offsetof(typeof(hdr), num_buffers),
				      sizeof hdr.num_buffers)) {
			vq_err(vq, "Failed num_buffers write");
			vhost_discard_vq_desc(vq, headcount);
			break;
		}
		vhost_add_used_and_signal_n(&net->dev, vq, vq->heads,
					    headcount);
		if (unlikely(vq_log))
			vhost_log_write(vq, vq_log, log, vhost_len);
		total_len += vhost_len;
		if (unlikely(total_len >= VHOST_NET_WEIGHT)) {
			vhost_poll_queue(&vq->poll);
			break;
		}
	}

	mutex_unlock(&vq->mutex);
}

static void handle_tx_kick(struct vhost_work *work)
{
	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
						  poll.work);
	struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);

	handle_tx(net);
}

static void handle_rx_kick(struct vhost_work *work)
{
	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
						  poll.work);
	struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev);

	handle_rx(net);
}

static void handle_tx_net(struct vhost_work *work)
{
	struct vhost_net *net = container_of(work, struct vhost_net,
					     poll[VHOST_NET_VQ_TX].work);
	handle_tx(net);
}

static void handle_rx_net(struct vhost_work *work)
{
	struct vhost_net *net = container_of(work, struct vhost_net,
					     poll[VHOST_NET_VQ_RX].work);
	handle_rx(net);
}

static int vhost_net_open(struct inode *inode, struct file *f)
{
	struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
	struct vhost_dev *dev;
	int r;

	if (!n)
		return -ENOMEM;

	dev = &n->dev;
	n->vqs[VHOST_NET_VQ_TX].handle_kick = handle_tx_kick;
	n->vqs[VHOST_NET_VQ_RX].handle_kick = handle_rx_kick;
	r = vhost_dev_init(dev, n->vqs, VHOST_NET_VQ_MAX);
	if (r < 0) {
		kfree(n);
		return r;
	}

	vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev);
	vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev);
	n->tx_poll_state = VHOST_NET_POLL_DISABLED;

	f->private_data = n;

	return 0;
}

static void vhost_net_disable_vq(struct vhost_net *n,
				 struct vhost_virtqueue *vq)
{
	if (!vq->private_data)
		return;
	if (vq == n->vqs + VHOST_NET_VQ_TX) {
		tx_poll_stop(n);
		n->tx_poll_state = VHOST_NET_POLL_DISABLED;
	} else
		vhost_poll_stop(n->poll + VHOST_NET_VQ_RX);
}

static void vhost_net_enable_vq(struct vhost_net *n,
				struct vhost_virtqueue *vq)
{
	struct socket *sock;

	sock = rcu_dereference_protected(vq->private_data,
					 lockdep_is_held(&vq->mutex));
	if (!sock)
		return;
	if (vq == n->vqs + VHOST_NET_VQ_TX) {
		n->tx_poll_state = VHOST_NET_POLL_STOPPED;
		tx_poll_start(n, sock);
	} else
		vhost_poll_start(n->poll + VHOST_NET_VQ_RX, sock->file);
}

static struct socket *vhost_net_stop_vq(struct vhost_net *n,
					struct vhost_virtqueue *vq)
{
	struct socket *sock;

	mutex_lock(&vq->mutex);
	sock = rcu_dereference_protected(vq->private_data,
					 lockdep_is_held(&vq->mutex));
	vhost_net_disable_vq(n, vq);
	rcu_assign_pointer(vq->private_data, NULL);
	mutex_unlock(&vq->mutex);
	return sock;
}

static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock,
			   struct socket **rx_sock)
{
	*tx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_TX);
	*rx_sock = vhost_net_stop_vq(n, n->vqs + VHOST_NET_VQ_RX);
}

static void vhost_net_flush_vq(struct vhost_net *n, int index)
{
	vhost_poll_flush(n->poll + index);
	vhost_poll_flush(&n->dev.vqs[index].poll);
}

static void vhost_net_flush(struct vhost_net *n)
{
	vhost_net_flush_vq(n, VHOST_NET_VQ_TX);
	vhost_net_flush_vq(n, VHOST_NET_VQ_RX);
}

static int vhost_net_release(struct inode *inode, struct file *f)
{
	struct vhost_net *n = f->private_data;
	struct socket *tx_sock;
	struct socket *rx_sock;

	vhost_net_stop(n, &tx_sock, &rx_sock);
	vhost_net_flush(n);
	vhost_dev_cleanup(&n->dev);
	if (tx_sock)
		fput(tx_sock->file);
	if (rx_sock)
		fput(rx_sock->file);
	/* We do an extra flush before freeing memory,
	 * since jobs can re-queue themselves. */
	vhost_net_flush(n);
	kfree(n);
	return 0;
}

static struct socket *get_raw_socket(int fd)
{
	struct {
		struct sockaddr_ll sa;
		char  buf[MAX_ADDR_LEN];
	} uaddr;
	int uaddr_len = sizeof uaddr, r;
	struct socket *sock = sockfd_lookup(fd, &r);

	if (!sock)
		return ERR_PTR(-ENOTSOCK);

	/* Parameter checking */
	if (sock->sk->sk_type != SOCK_RAW) {
		r = -ESOCKTNOSUPPORT;
		goto err;
	}

	r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa,
			       &uaddr_len, 0);
	if (r)
		goto err;

	if (uaddr.sa.sll_family != AF_PACKET) {
		r = -EPFNOSUPPORT;
		goto err;
	}
	return sock;
err:
	fput(sock->file);
	return ERR_PTR(r);
}

static struct socket *get_tap_socket(int fd)
{
	struct file *file = fget(fd);
	struct socket *sock;

	if (!file)
		return ERR_PTR(-EBADF);
	sock = tun_get_socket(file);
	if (!IS_ERR(sock))
		return sock;
	sock = macvtap_get_socket(file);
	if (IS_ERR(sock))
		fput(file);
	return sock;
}

static struct socket *get_socket(int fd)
{
	struct socket *sock;

	/* special case to disable backend */
	if (fd == -1)
		return NULL;
	sock = get_raw_socket(fd);
	if (!IS_ERR(sock))
		return sock;
	sock = get_tap_socket(fd);
	if (!IS_ERR(sock))
		return sock;
	return ERR_PTR(-ENOTSOCK);
}

static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
{
	struct socket *sock, *oldsock;
	struct vhost_virtqueue *vq;
	struct vhost_ubuf_ref *ubufs, *oldubufs = NULL;
	int r;

	mutex_lock(&n->dev.mutex);
	r = vhost_dev_check_owner(&n->dev);
	if (r)
		goto err;

	if (index >= VHOST_NET_VQ_MAX) {
		r = -ENOBUFS;
		goto err;
	}
	vq = n->vqs + index;
	mutex_lock(&vq->mutex);

	/* Verify that ring has been setup correctly. */
	if (!vhost_vq_access_ok(vq)) {
		r = -EFAULT;
		goto err_vq;
	}
	sock = get_socket(fd);
	if (IS_ERR(sock)) {
		r = PTR_ERR(sock);
		goto err_vq;
	}

	/* start polling new socket */
	oldsock = rcu_dereference_protected(vq->private_data,
					    lockdep_is_held(&vq->mutex));
	if (sock != oldsock) {
		ubufs = vhost_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock));
		if (IS_ERR(ubufs)) {
			r = PTR_ERR(ubufs);
			goto err_ubufs;
		}
		oldubufs = vq->ubufs;
		vq->ubufs = ubufs;
		vhost_net_disable_vq(n, vq);
		rcu_assign_pointer(vq->private_data, sock);
		vhost_net_enable_vq(n, vq);

		r = vhost_init_used(vq);
		if (r)
			goto err_vq;
	}

	mutex_unlock(&vq->mutex);

	if (oldubufs) {
		vhost_ubuf_put_and_wait(oldubufs);
		mutex_lock(&vq->mutex);
		vhost_zerocopy_signal_used(vq);
		mutex_unlock(&vq->mutex);
	}

	if (oldsock) {
		vhost_net_flush_vq(n, index);
		fput(oldsock->file);
	}

	mutex_unlock(&n->dev.mutex);
	return 0;

err_ubufs:
	fput(sock->file);
err_vq:
	mutex_unlock(&vq->mutex);
err:
	mutex_unlock(&n->dev.mutex);
	return r;
}

static long vhost_net_reset_owner(struct vhost_net *n)
{
	struct socket *tx_sock = NULL;
	struct socket *rx_sock = NULL;
	long err;

	mutex_lock(&n->dev.mutex);
	err = vhost_dev_check_owner(&n->dev);
	if (err)
		goto done;
	vhost_net_stop(n, &tx_sock, &rx_sock);
	vhost_net_flush(n);
	err = vhost_dev_reset_owner(&n->dev);
done:
	mutex_unlock(&n->dev.mutex);
	if (tx_sock)
		fput(tx_sock->file);
	if (rx_sock)
		fput(rx_sock->file);
	return err;
}

static int vhost_net_set_features(struct vhost_net *n, u64 features)
{
	size_t vhost_hlen, sock_hlen, hdr_len;
	int i;

	hdr_len = (features & (1 << VIRTIO_NET_F_MRG_RXBUF)) ?
			sizeof(struct virtio_net_hdr_mrg_rxbuf) :
			sizeof(struct virtio_net_hdr);
	if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) {
		/* vhost provides vnet_hdr */
		vhost_hlen = hdr_len;
		sock_hlen = 0;
	} else {
		/* socket provides vnet_hdr */
		vhost_hlen = 0;
		sock_hlen = hdr_len;
	}
	mutex_lock(&n->dev.mutex);
	if ((features & (1 << VHOST_F_LOG_ALL)) &&
	    !vhost_log_access_ok(&n->dev)) {
		mutex_unlock(&n->dev.mutex);
		return -EFAULT;
	}
	n->dev.acked_features = features;
	smp_wmb();
	for (i = 0; i < VHOST_NET_VQ_MAX; ++i) {
		mutex_lock(&n->vqs[i].mutex);
		n->vqs[i].vhost_hlen = vhost_hlen;
		n->vqs[i].sock_hlen = sock_hlen;
		mutex_unlock(&n->vqs[i].mutex);
	}
	vhost_net_flush(n);
	mutex_unlock(&n->dev.mutex);
	return 0;
}

static long vhost_net_ioctl(struct file *f, unsigned int ioctl,
			    unsigned long arg)
{//printk("invoke vhost_net_ioctl\n");
	struct vhost_net *n = f->private_data;
	void __user *argp = (void __user *)arg;
	u64 __user *featurep = argp;
	struct vhost_vring_file backend;
	u64 features;
	int r;

	switch (ioctl) {
	case VHOST_NET_SET_BACKEND:
		if (copy_from_user(&backend, argp, sizeof backend))
			return -EFAULT;
		return vhost_net_set_backend(n, backend.index, backend.fd);
	case VHOST_GET_FEATURES:
		features = VHOST_FEATURES;
		if (copy_to_user(featurep, &features, sizeof features))
			return -EFAULT;
		return 0;
	case VHOST_SET_FEATURES:
		if (copy_from_user(&features, featurep, sizeof features))
			return -EFAULT;
		if (features & ~VHOST_FEATURES)
			return -EOPNOTSUPP;
		return vhost_net_set_features(n, features);
	case VHOST_RESET_OWNER:
		return vhost_net_reset_owner(n);
	default:
		mutex_lock(&n->dev.mutex);
		r = vhost_dev_ioctl(&n->dev, ioctl, arg);
		vhost_net_flush(n);
		mutex_unlock(&n->dev.mutex);
		return r;
	}
}

#ifdef CONFIG_COMPAT
static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl,
				   unsigned long arg)
{
	return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
}
#endif

static const struct file_operations vhost_net_fops = {
	.owner          = THIS_MODULE,
	.release        = vhost_net_release,
	.unlocked_ioctl = vhost_net_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = vhost_net_compat_ioctl,
#endif
	.open           = vhost_net_open,
	.llseek		= noop_llseek,
};

static struct miscdevice vhost_net_misc = {
	MISC_DYNAMIC_MINOR,
	"vhost-net",
	&vhost_net_fops,
};

static int vhost_net_init(void)
{
	struct proc_dir_entry *vhost_proc;
	struct proc_dir_entry *vhost_ctl_proc;
	vhost_proc = create_proc_entry("vhost", 0777, NULL); //Under the current kernel API, pass NULL for the root of procfs.instead of create_proc_entry, you should use proc_create() with a proper const struct file_operations *.
	if (vhost_proc == NULL) {
		remove_proc_entry("vhost", NULL);
		printk(KERN_ALERT "Error: Could not initialize /proc/vhost\n");
		return -ENOMEM;
	}
	else {
		printk(KERN_ALERT "Add read_proc function for /proc/vhost\n");
		vhost_proc->read_proc=(read_proc_t *) procfile_read;
		//vhost_proc->proc_fops = &my_file_ops;
	}
	spin_lock_init(&proc_lock);
	//recordlist = (char *)kmalloc(1024*1024, GFP_KERNEL);
	//recordlist_offset = 0;

	//remove_proc_entry("vhost-ctl", NULL);
	vhost_ctl_proc = create_proc_entry("vhost-ctl", 0777, NULL);
	if (vhost_ctl_proc == NULL) {
		remove_proc_entry("vhost-ctl", NULL);
		printk(KERN_ALERT "Error: Could not initialize /proc/vhost-ctl\n");
		return -ENOMEM;
	}
	else {
		printk(KERN_ALERT "Add write_proc function for /proc/vhost-ctl\n");
		vhost_ctl_proc->write_proc=(read_proc_t *) ctl_procfile_write;
		vhost_ctl_proc->read_proc=(read_proc_t *) ctl_procfile_read;
		//vhost_proc->proc_fops = &my_file_ops;
	}

	if (experimental_zcopytx)
		vhost_enable_zcopy(VHOST_NET_VQ_TX);
	return misc_register(&vhost_net_misc);
}
module_init(vhost_net_init);

static void vhost_net_exit(void)
{
	//list_del_init(&mydrv_list);
	truncate_list();

	remove_proc_entry("vhost", NULL);
	printk(KERN_ALERT "Remove /proc/vhost\n");
	remove_proc_entry("vhost-ctl", NULL);
	printk(KERN_ALERT "Remove /proc/vhost-ctl\n");
	misc_deregister(&vhost_net_misc);
}
module_exit(vhost_net_exit);

MODULE_VERSION("0.0.1");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Michael S. Tsirkin");
MODULE_DESCRIPTION("Host kernel accelerator for virtio net");
